Electric signaling system.



A. BULI.

BLEGTRIG SIGNALING SYSTEM.

APPLICATION FILED JUNE 29, 1911.

1,1 10,479, Patented Sept. 15,1914u 4 SHEETS--SHEET 1.

THE NORRIS PETERS CO., PHOTO-LITHO., WASHING I'ON. D CV A. BULL.

BLBCTRIG SIGNALING SYSTEM.

APPLIUATION FILED JUNE 29, 1911.

1,1 10,4179. l Y Patented sept.15,1914.,

4 SHEETS-SHEET L A I l VII- VII-l FLL THE NORRIS PETERS CO., PHOTD-LIVTHO., WASHINGTDN. D. C.

A. BULL. ELECTRIC SIGNALING SYSTEM.

APPLIOATION FILED JUNE 29, 1911.

1 1 1 0,479. Patented Sept. 15, 1914 4 SHEETS-SHEET 3` vmmhmwww THE NORRIS PETERS CQ, PHOTO-LITHO., WASHINGTON, D. CV

A. BULL.

ELECTRIC SIGNALING SYSTEM.

APPLICATION FILED JUNE 29, 1911.

1 ,1 1 0,479, Patented Sept. 15, 19141` 4 SHEETS-SHEET 4.

THE NORRIS PETERS CO.. PHOTOLITHO. WASHINGTON. D. C.

NTED STATES PATENT FFICE.

ANDERS BULL, 0F BROOKLYN, NEW YORK.

ELECTRIC SIG-NALING SYSTEM.

Griginal applioatonled June 25.1916, Serial No. 568,781. Divided and this application filed June 29, f

Specification of Letters Patent.

Patented Sept. 15, 1914.

isii. sensi No. 636,090.

To @Hw/1,0m k1/may concern: i Be it known that Animes BULL, a citi- Zen of the United States, residing in Brook-v f lyn, in the county of Kings and Sta-te of from which transmitter, the signals have been sent.

rIhe system is especially intended for Vindicating ie positions and recording the movements of trains along aA railroad line. To this purpose are placed, at equal intervals along the line, transmitters,which are all connected to a central receiver or recorder. The mechanical energy required forV operating the transmitters is Y supplied by the passing trains, and while the transmitters thus energized are, to a certain extent, controlled by the receiver, a reaction also takes place affecting the receiver. As the latter is atfected dierently by different transmitters it is thuspossible to locateea transmittervthat has, at a certain time, been passed by a train. To this purpose series of impulses are used or'operating the-apparatus, the word impulse referring broadly to any change inthe intensity oli' the line current. dii'ierent kinds which will be referred to in the following as regular impulses and special impulses respectively.

ln order to eilect the transmission of a signal a complete series is required, consisting or one ormore regular impulses and a certain number of special impulses (which latter number may also be one). `The regular impulses are used Viior controlling the movement of certain parts'in such transmitters as, having been energized by a passing t `ain, are ready to send a signal. The special impulses are used for the transmission of the signal proper.

The special impulses or"V a series may be timed in different ways relative to the regular impuls@ (or impulses) oi2 the same series, and as the special impulses are produced through the instrumentality of the transmitter it 'is possible to thus adjust a number of transmitters, that the special impulses due to each are timed in 'a'distinct Way. f

1While the regular impulses will ali'ect theA` transmitters only, the special impulses will affect the receiver only. According to the way the special yimpulses ,of a series are timed, their eiect on the receiver will be 2 and 3 represent diilerent viewsV of a re` ceiver constructed for series containing' six regular and three special impulses. Figs.

- aud 5 represent outside and inside views Y f of a. transmitter adapted-to operate said receiver. Fig. 6 shows graphically some different forms of series, each containing six regular impulses. YFig. 7' shows a receiver and a transmitter constructed for series consisting of' one regular impulse and three special impulses. Fig. 8 shows graphically some diterent forms of series, each containing one regular impulse. Fig. 9 shows a receiver vand a transmitter constructed for seuniform speed in the direction indicated by an arrow by a motor` acting through the pulley 2 and Worm gear 3.

To said spindle is fastened a rod 1l carrying a brush 5 which y is adapted to slide over a `number of contact pieces 6, 7. The contact piecest are connected directly to the line wire 10 While" the brush is connected through the spindle to one polev of the battery 8, the other pole of which is connected to the line Wire '9.

rlhe contact pieces 7 are connected to the line wire lO through the Wires 38, 39 and the windings of the electromagnet 11 l) which is fixed to a frame l2 resting on uprights 13. rThe pole piece of the magnet is bent at right angles so that it faces the" center of thel spindle l. lits armature is xed to a trigger, or selector le pivotedin v a bracket on the disk 16 which is secured to the spindle. Being arranged concentrically with the disk the armature will, during the rotation of the spindle, remain in the same position to the pole piece of the magnet, turning only around its own center. Vhen the magnet is energized the armature is attracted and the pointed end of the trigger 14 is lowered toward the disk 16 until it assumes the position shown in Fig. 12. In this position it will strike a number of hooks 17, while in its former position (shown in Fig. 2) it will pass clear of them.

Each of the hooks 17 (see also Figs. 11 and 12) is pivoted to the free end of a lever 18 which is rigidly connected with another lever 19, the connecting bolt 2O passing through the frame 12 and acting as a pivot. The lever 19 communicates through a link 21 'withthe lever 22 which is fixed to a shaft 23. Said shaft is run through both walls of the casing and carries at its other end a l-.ver 2l v(Fig. 3l corresponding to the horizontal part of the lever 22, the two latter ,levers being furthermore connected through a rod which is put through oblong holes2G in a large number of vertical combination bars 27. f

r1 spring 2S, bearing against the lever 22, would force the rod 25 downward but for the hook 17 enOaging a pin 29 on the frame 12.V 1r", however, the point of the trigger 14V is lowered it will, in passing the hook, disengage the latter by unhooking it from its pin. T ie lever 22 which is thereby released..l will yield to the pressure of the spring until it strikes the stop 15, the result being a lowering of the rod The process just described is illustrated v by Figs. 11 to 14, which give enlarged front and side vviews of one ot the hook combinations immediately before (Figs. 11 and 12) and after (Figs. 13 and a release of the hook 17, shaded parts representing sections.

The recorder shown has six hooks, each connected in the way described with a rod passing through the bars 27, as shown in Fig. 1. 1n Fig. 2 one hook combination only is vshown complete, some parts having been omitted in order to not obscure the drawing.

The angular distance between the hooks is the same as between the contact pieces 7, and the brush holder 4 is secured to the spindle in such a position to the trigger 1t that when the point of the trigger is about to pass a hook, the brush will be in contact with one of the contact pieces 7, one pole of the magnet 11 being thus connected to the battery. Since the other pole of the magnet is permanently connected to the line wire 10 a current will trav rse the magnet if the line wires are short-circuited during said contact. In this case the armature of the magnet is attracted and the point ol the trigger 14: lowered so as to disengage the hook. Any of the hooks 17 may thus be disengaged by short-circuiting the line wires while the brush is sliding over the corresponding contact piece 7.

vVhen a hook has been disengaged it will remain so until the spindle 1 has made almost a complete lrevolution when it is brought back into its former position by a lug 30 which is Jfastened to the disk 16. 1n passing the tree end of the lever 19 the lug will :torce it outward, and since the lever 19 is rigidly connected with lever 18, the hook is pushed toward the spindle so that it again engages the pin 29, while at the same time the rod 25 is raised. Y

Independently of the rods already mentioned, an additional rod 31 is run through the bars 27. The latter rod is forced upward by a spring 32 bearingagainst one of its supports, and is interlinked with a lever which is pivoted in the frame 12.V During the rotation of the spindle the lug 30 will also impinge on the lever 33, the result being a transient depression of the rod 31.

The vertical bars 27 fit loosely into narrow slots in a pair of brackets 34 so that they may be raised and lowered without appreciable Jfriction. Their upper ends are shaped into hooks grasping the elastic stems of a corresponding number of pens 35. When a bar is lowered its weight will press the corresponding pen against a moving paper sheet 36. To insure a true movement of the pens their stems are put through ver tical slots in the bracket 37.

The holes 26 are of different sizes, some of them being wider in a vertical direction than the rest. While in the bar visible in Fig. 1, the first, third and fifth hole from the top afford clearance above as well as underneath the rods, the other holes in that bar afford clearance underneath only. Therefore, while the holes in said bar will allow any of the rods 25, 31 free play to be lowered the bar itselt can not be lowered unless the second,

'fourth and sixthY rod (from the top) have first been lowered through disengagement of the hooks connected with them. 1f this has been done the bar is held up by the rod 31 only, so when the latter is depressed by the lug 30 striking the lever 33 the bar is also depressed for a short time and a dot is printed on the moving sheet by the first pen to the left'in Fig. 2. rThe first, third andrfiith rod remaining in position will not obstruct a lowering of said bar on account of the upper clearance afforded by the wider holes.

While the bars 27 have all the same number of holes, the relative order of the six upper holes is varied from one bar to another. Three of these holes being wide and three narrow, their relative order may be varied in 6 5 ll/1 2 3, or 20, diierent ways, and an equal number of bars is shown in the diagram.

In order to effect the depression of any of these bars, three of the rods 25 have rst to be lowered, the location of the three rods being given by the location of the three narrow holes in the bar to be depressed, and as the location of said holes is never the same in two bars, the lowering of the three rods .in question will result in the depression of that particular bar only. 'Any of the twenty pens 35 may thus be operated by short-eir-` cuiting the line wires while the brush 5 is sliding over three of the contact piecesV 7.

The transmitter shown in Figs. 4 and 5 is worked by a clock-work which is wound only when a signal is to be sent. It the system is used :tor the recordingV of train movements the winding is done automatically whenever a transmitter is passed by a train. To this purpose a projection 50 on the train is supposed to strike and depress a lever 51, fixed to the shaft-52- The lever 55,v which is connected with the shaft through the parts 53 and 54, is thereby raised, causing the pawl 56- to engage' the next tooth on the ratchet 57. When the lever 51 is subsequently released' a spring 58 will immediately return the levers to the position shown, and the ratchet wheel is thus turned an angle determined byits pitch A. rotative force is thereby applied, through the spiral spring 59, to the gear wheel 60 which, it free to move, willl turn until stopped by a pin 61, projecting from the ratchet through the slot 62. The gear wheels are so dimensioned that when said movement is completed the spindle 63 will have been put through one complete revolution, in the direction indicated by an arrow in Fig. 4.

The rotation ot the spindle is controlled by the magnet 70. A pawl 64, attached to the armature of said magnet, is pressed by a spring 74 against the ratchet disk 66 which is fixed to the spindle. 1n this position the pawl will engage teeth 65, 73 on vthe disk and thus prevent the spindle 63 from rotating. The disk carries a brush 67 adapted to slide over contact pieces 68, 69, 72. rlhe shorter contact pieces y68, 72, which are arranged in the same way in all the transmitters, are connected to one pole ot the magnet 70. The longer contact pieces 69, which are arranged diiierently in diii'erent transmitters, are connected to the line wire 10, as is the other pole of the magnet 70. The brush 67 is connected to the line wire 9 through the disk 66 and spindle 63. The wires 9 and l0 in Fig. 4 are parts of the wires similarly designated in Fig. 3.

During the arrested positions ot' the disk 66 the brush 67 will always be in contact with one ofthe shorter contaot'pieces, vand the magnet 7 0 will then be connected across the line wires 9, 10. A contact between the brush and one of the longer contactpieces will cause the line wires to be short-crcuited- Y lhen the magnet 70 is traversed by ay current the pawl 64 is withdrawnand the disk 66, which isthereby released, starts rotating. By properly adjustingfthe retardin'g eiiect ci' a vane 71 the speed of rotation Vmay be thus regulated, in relation to that of the Y recorder spindle (l, Fig. that the transmitter brush will cover the distance between twooijits shorter Contact pieces in slightly less time than willfthe recorder brush (5, F ig. 3). Thus, in Vthe apparatus shown 'in Figs. l to 5, the transmitter spindle 63 is supposed to rotate with a speed which is.y

parts 68, 67, 66, 63, wire 9 and back tothe battery. ySince kthe magnet 70 is thereby energized the disk 66 is released and starts rotating.

While the receiver brush is moving yfrom f the first to the second ot the contact pieces 6V the transmitter brush will move from the Vfirst to the second ofthe contact pieces 68.

The vane 71 being'properly adjusted, the disk 66 will have been'l arrested by the pawl 64 just'before a Contactr is established between the brush 5.and the second orn the contact pieces 6. v4When the latter contact is` made another current impulse is sent through the magnet 70 and the disk 66 is released for the second time.

The process just described is repeatedfor each of the following contact pieces 6, so

when a contact is established between the brush 5 and the sixth of the contact pieces 6, the disk 66 will be released for the siXth time. Vhile moving from the position shown by full lines in Fig. 4, to the one shown by dotted lines, the brush 67 will, to all practical purposes, move synchronously with the brush 5, for although the movement of brush 67 is intermittent whilethat of brush 5 is continuous the periods during which the disk 66 remains arrested during this part of its revolution are comparatively short; while the brush 67 is sliding over one or" the contact pieces 69 the brush 5 will, therefore, be sliding over one of the contact pieces 7.V

In the transmitter shown the contact pieces 69 are placed so as to be touched by the brush uponthe second, fourth and sixth releaseof the disk 66, which means that the linewires will be short-circuited while the receiver brush is in Contactr with the second,

fourth and sixth of theV contact pieces 7. As above stated this will result in a depression of the first bar to the left in Fig. 2, adot being printed on the moving sheet 36 by the pen directly above said bar.

ln thearrangement described the current imgulses produced while the receiver brushV o V1s sliding over the contact pieces 6 represent the regular impulses of a series, while the current impulses produced while the transmitter brush 67 is sliding over the contact pieces 69 represent the special impulses of a series.

rlhe complete series, resulting from an operation of the transmitter shown, is graphically represented by A in Fig. 6, where the regular impulses are indicated by blank rectangles on a horizontal line, representing time, while the special impulses are indicated by shaded rectangles. The number of contact pieces 69 is the same in all the transmitters but, as in each transmitter said contact pieces are arranged differently relative tothe contact pieces 68, the consecu?v tive order of the regular and specialgimpulses will be different in series resulting from the operation of different transmitters. Thus B in Fig. 6 represents a series due to the operation of another transmitter. ln the latter series the first, second and sixth of the regular impulses are each followed by a special impulse, indicating that the line wires are being short-circuited while the receiver brush is sliding over the first, second and sixth of the contact pieces 7. Series B will, therefore, cause the first, second and sixthv (from the top) of the rods 25 in the receiverto be lowered. The pen grasped by the bar having its holes arranged so that the first, second and sixth hole from the top are narrow ones will thereby Vbe operated.

The contact pieces 69 may be arranged in twenty different ways, and twenty transnitters may thus be connected to the recorder, each acting upon a dierent pen. By the position of the dots printed on the moving sheet 36, the location of transmitters passed by trains as well as the time of passage may be ascertained, the rate at which the sheet is unwound being known.

If'arrangements are made assigning the first pen to the left in Fig. 2 to the nearest transmitter, and the second, third, fourth, pen to transmitters placed at distances increasing with the serial number of the pen, then the dots produced by a train moving along the line will arrange themselves into a curve having distance and time as coordinates. Each separate train will be recorded by a distinct curve, and from such curves all essential features o-f the t-rain movements may be determined, as momentary whereabouts, speeds, headways, stops, etc.

It may hap-pen that a transmitter is energized at a time when the receiver brush 5 has already left the first of the contact pieces 6, 7, having, however, not yet passed the last. in this case, if the brush 67 would start from the position shown by full lines in F ig. 4, said brush would not, during its further movement, have the right position relative to the brush 5 in the receiver, but be lagging behind. This would interfere with the proper transmission of the signal, since the special impulses would thereby be displaced in relation to the regular impulses and the rods 25 lowered in wrong order. To preventthis possibility1 the Contact piece 72and the toothl73 (Fig. 4) have been provided. Y

is long as the transmitter is not worked the brush .67 will be in the position shown to the left by dotted lines while the pawl will rest against the disk at a point located somewhere between the tooth 73 and the nearest onev of the teeth lWhen the transmitter is energized the spindle 63 immediately starts rotating and the brush 67 is moved into contact with the piece 72 in which position it is stopped by the pawl 64 engaging the tooth 73. Any impulse trav` ersing the magnet will now release the disk 66.

Assuming that the impulse effecting such release is produced by t-he brush 5 sliding over the first of the contact piecesY 6, then, by the time brush 5 has slid over the entire set of contact pieces 6, 7, brush 67 will have covered an angle which, though less than 180o, is somewhat larger than the angle embraced by the contact pieces 68, 69 since during this part of its movement the disk 66 is never stopped, there being no teeth to engage the pawl 64 until the disk has attained the position shown in Fig. 4l, As no new impulse will be produced until brush 5 again touches the first of the contact pieces 6, the disk will remain arrested in this position until another series is started.

On the other hand, if the impulse first vtraversing the magnet 70 is produced by the brush sliding over the last of the contact pieces 7 the disk 66 will start toward the position shown before brush 5.has left said contact piece. The disk 66, having a higher speed and a smaller angle to turn than the brush 5, will, therefore, reach (and be arrested in) the position shown before said brush has again touched the first of the contact pieces 6.

The general case being embraced by the two extremes here given, it does not. matter through which of the contact pieces 6, 7 theimpulse first releasing the disk 66 has been produced: by the time the brush 5` again reaches the first of the contact pieces 6 the transmitter brush 67 will be in the position shown by full lines, and the two brushes will now have the right relativeV position. It may also occur that several transmitters are simultaneously energized. The brushes in these transmitters will then be put through corresponding movements at the same time, and theA series thus produced will be a combination of the series produced when the same transmitters are operated singly. This will, however, not interfere with the transmission of the signals. f

If, for instance, the transmitters represented by series A and B in Fig. 6 are siinultaneously energized the resulting series will be as shown by E, and the first, second, fourth and sixth (from the top) of the rods 25 will be lowered in the recorder. As the bars 27 are not influenced by the lowering of rods put through their wider holes, the signals from both transmitters will consequent-ly be registered. Y

In the transmitter shown in Figs. 4 and 5, only a rough adjustment of the vane 71 is required in order to keep the speed of rotation `of the rspindle 63 within the proper limits. According to the above, this speed must be high enough for the brush 67 to be arrested between each of the regular impulses rrequired for putting the disk 66 through the second half of its revolution. This provided, it is of no consequence Whether said speed is ten per cent. higher than that of the recorder spindle, as stated above, or, say, eight or twelve per cent.

higher. The two per cent, more or less will have no perceptible eifect since the position of the brush 67 is corrected at every release of the disk G6.

In fact, after the disk hasbeen released from the position shown, by the irstregu lar impulse of a series, the following regular impulses of the same series serve the purpose only of cont-rolling the subsequent rotation of the disk so as to render unnecessary a very delicate adjustment of the speed. In cases where a delicate adjustment forms lno objection, the latter regular impulses may be omitted, only the first regular impulse being left. f

The apparatus shown in Figsl to 5 may be adapted to the latter kind of series by omitting all yexcept the iirst of the contact pieces 6 (F ig. 3), as well asfall except the rst ofthe contact pieces 68 and the teeth 65 (Fig. 4), all other parts being retained.

v `The apparatus thus modified are shown in Fig. 7. When the brush 67 has reached the position shown, the regular impulse pro duced when the brush 5 is sliding over the contact piece 6', will release the disk 66, which will rotate at a practically uniform speed until its revolution has been completed. During this movement, While the brush 67 is sliding over the contact pieces 69V the brush 5 will be sliding over' the second,

fourth and sixth of the contact pieces 7 the j E', Fig. 8, willlhave the same eEects as the series designated by corresponding letters in Fig. 6. .j j A. .j rlChe construction shown in Fig. 9 represents a compromisebetween the constructions shown in Figs. l to 5 and Fig. 4, the apparatus being designed for series contain ing two regular impulses each. To this purpose four of the contact pieces 6, Fig. 3, as well as four of the contact pieces 69 and the teeth 65, Fig. 4, have been omitted, the contact pieces 6 and 69 and. the teeth 65 in Fig. 9 having the saine place as the first and fourth of thesiinilar parts in Figs. 3 and 4. The speed of the dislr 66 is so adjusted that, upon beingv released in the position shown, by the first regularl impulse of a series, the briisli`67 is arrested, in contacty with the second contact piece 68, just before the second regular impulse of the series is produced.

- In kthe transmitter shown inyFig. 9 .the brush 67 will then slide over the contact pieces 69 while, the brush 5 in the receiver is sliding over the second, fourth and sixth of the contact pieces 7, and the resulting series, A in Fig. l0, will thus have the same effect upon the receiver in Fig. 9 as has series A. in Fig. 6 upon the'receiver first described. Likewise series B to E in Fig. 10 will have the same eifect as the series similarly designated in Fig. 6.

Since corresponding series will have the same effect in all the three cases, kthea-pparatus shown in Figs. 7 and 9 may be used to the sameL advantage as may the apparatus shown in Figs. l to 5. In fact, the receiver shown in Figs. l to 3 could be used, without any alteration, for any of the three types of transmitters. Y

I claim: l

l. In a signaling system, thev combination with a line circuit and a source of electric energy, of a central apparatus having' means for producing electric impulses inthe line r circuit, a. plurality of transmitters; each` transmitter including a movable member 66, electromagnetic means operable by sardinipulses for controlling the movementof said member, means 69 operable through.r said n inthe line circuit, a plurality of transmit f ies ters; each transmitter including a movable member (56, electromagnetic means operable by said impulses for controlling the movement of said member, means 69 operable through said member for controlling the line current during a number of prearranged periods; each of said periods folien/*ing one of said impulses, and electromagnetically operable means controlled by the line current during said periods.Y

3. ln a signaling system, the combination with a line circuit and a source of electric energy, of a central apparatus, a plurality of transmitters; each transmitter including a movable member G6, means adapted to be set for moving said member, means operated by line current produced by said central apparatus and adapted to control the movement of said member after the first means have been set, means 69 operated through said member for controlling the line current during one or more periods following an operation of said movement controlling. means, electromagnetic means operable by line current due to the operation of said current controlling means, and a set of selectable devices controllable by said electromagnetic means; each of said devices being operable at a dierent time.V Y

4. In a signaling system of the character described, the combination with a line circuit and a source of electric energy, of a central apparatus having means for producing electric impulses, a plurality oi' transmitters; each transmitter including a movable member 66, means adapted to be operated by said impulses for controlling they movement of said member, means 69 operated through said member for controlling the line current during a plurality of periods; said periods having a distinct time order relative to one or more of said impulses; said time order depending on the adjustment of said current controlling means, and means controlled by the line current during said periods.

5. 1n a signaling system of the character described, the combination with a line circuit and a source of electric energy, of a central apparatus having means for producing electric impulses, a plurality of transmitters; each transmitter including a movable member 66, driving means Jfor moving said member at aprearranged rate, means operable by impulses produced by said central apparatus for Acontrolling the movement of said member, means controlled by said member for closing the line circuit during prearranged phases of said movement for the purpose of producing current impulses having a distinct time relation to said electric impulses, electromagnetic means operable by said current impulses, a set of devices operated selectively by said electromagnetic means, and a set of combination bars; each combination bar responding to the operation of a distinct group of said devices. Y

5. in a signaling system of the character described, the combination with a line circuit and a source of electric energy, of a central apparatus having means i'or producing a number of regular current impulses in the line circuit, a plurality of transmitters; each transmitter including a movable member, driving means for moving said member ata prearranged rate, means operable by said regular impulses for controlling the movement of said member, means operable in distinct positions orn said member for producing special current impulses having a prearranged time relation to one or more of said regular impulses, electromagnetic means responding to said special impulses, a set of selectable means operable consecutively by said electromagnetic means according to said time relation, a set of combination bars; each combination bar responding to the operation of a distinct group of said selectable means, and means for recording the operation of each of said combination bars.

7. In a signaling system of the character described, the combination With a line circuit and a source of electric energy, of a central apparatus having means for periodically producing a number of electric impulses in the line circuit, a plurality of transmitters; each transmitter including power storing means, a member driven by said power storing means, means operable by said impulses for arresting said member in diil'erent positions, speed retarding means making the time consumed for a cyclic movement of said member longer than the period of said impulses, and means operated in distinct positions of said member for producing current impulses having a distinct time relation to the impulses produced by said central apparatus.

8. In a signaling system of the character described, the combination with a line circuit and a source of electric energy, of a central apparatus having continuously operated means for producing electric impulses, selective'means having a-cordinate movement with said continuously operated means and controlled by line current during periods following said impulses, selectable means operable through said selectivemeans during said periods, a set of combination bars; each combination bar responding to the cperation of a distinct group of said selectable means, and a plurality of transmitters; each transmitter having means operable by said impulses for controlling the line current during some of said periods.

9. In a signaling system of the characterV described, the combination with a line circuit and a source of electric energy, of a central apparatus having means for periodically producing a number of electricimpulses in tlie line circuit, a plurality of transmitters; each transmitter including means for deriving energy from passing trains or other sources, means for storing said energy, a member tending to move under the in uence oi' said energy, a ratchet and pavvl for arresting said member in different positions, an eleotromagnet for operating said pawl, means for regulating the speed of said member upon the latter being released, a contact brush rotating with said member, a set of contact pieces coperating with said brush for connecting said electromagnet across the line Wires during arrested positions of said member, a second set of contact pieces cooperating with said brush for intert connecting the line Wires during prearv ranged, non-arrested positions of said member and arranged differently in different transmitters, and means respondingto line current produced during the operation of said second set of contact pieces.

- ANDERS BULL. Vitnesses :v

JOHN CoornRsTooK, PHILIP SACHS;

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C." Y 

